Crotoxin acceptor protein isolated from Torpedo electric organ: binding properties to crotoxin by surface plasmon resonance.

Crotoxin, a potent neurotoxin from the South American rattlesnake Crotalus durissus terrificus, is a heterodimeric phospholipase A(2) (EC 3.1.1.4), which blocks the release of acetylcholine from peripheral neurons. We previously have suggested the existence of a 48 kDa crotoxin-binding protein in the presynaptic membranes of the electric organ of Torpedo marmorata. Here, we report the purification and characterization of this protein that we called the crotoxin acceptor protein from Torpedo (CAPT). The membranes of electric organs from Torpedo were solubilized with a detergent (4% (w/v) Triton X-100) and CAPT was isolated by affinity chromatography on a crotoxin column. SDS-PAGE showed that the purified protein was homogeneous and cross-linking studies with radioiodinated crotoxin confirmed that it had retained its toxin-binding properties. The purified CAPT has similar molecular mass as crocalbin, a crotoxin-binding protein isolated from porcine brains, yet anti-crocalbin antiserum failed to recognize CAPT. Surface plasmon resonance biosensor technology was used to measure the specific interaction between crotoxin and solubilized CAPT. Using this method, it was possible to follow CAPT throughout the purification procedure. As well, an apparent dissociation constant (K(d)(app)) of 3.4 nM was calculated for the interaction of pure CAPT and crotoxin from the dissociation rate constant (k(off)=1.2 x 10(-2)s(-1)) and the association rate constant (k(on)=3.5 x 10(6)M(-1)s(-1)).     

Blockade of the expression of mecamylamine-precipitated nicotine withdrawal by calcium channel antagonists.

The present study focused on the evaluation of nicotine abstinence syndrome in mice and on the influence of calcium channel blockers on the expression of the somatic signs of nicotine withdrawal. Our experimental protocol consisted of intermittent administration of nicotine, 2.5 mgkg(-1), subcutaneously (s.c.), four times daily for 7 days. In attempt to precipitate nicotine abstinence, mice were given one injection of mecamylamine (3 mgkg(-1), intraperitoneally (i.p.)), 1h after the last nicotine injection, on the test day (day 8) in the morning. Additionally, body weight changes, locomotor activity and anxiogenic responses in the elevated plus maze test were also evaluated in nicotine withdrawn mice. Our data shown that the L-type calcium channel antagonists, nimodipine, verapamil, flunarizine and diltiazem (5 and 10 mgkg(-1), i.p., each), injected before mecamylamine administration, dose-dependently attenuated the expression of nicotine withdrawal signs. Moreover, 24h after terminating nicotine treatment, we also observed additional nicotine abstinence measures, such as loss of body weight followed by a slight body weight gain, decrease of spontaneous locomotor activity and anxiogenic responses. These findings obtained using our valuable rodent model of nicotine dependence suggest the involvement of calcium-dependent mechanisms in the expression of mecamylamine-precipitated nicotine abstinence syndrome.     

Operative treatment of benign ovarian tumours in adolescent patients: laparotomy or laparoscopy?

THE AIM: The aim of the study was a retrospective analysis of operative procedures, laparoscopy or laparotomy, carried out in cases of benign adolescent ovarian tumours. MATERIAL AND METHODS: A retrospective review of 709 patient charts with ovarian tumours, who had undergone surgical interventions at The Department of Surgical Gynaecology and Endoscopy of The Polish Mother's Memorial Hospital--Research Institute in ?ód?--has been conducted. Among groups of girls treated either with laparoscopy or laparotomy, the following parameters were analysed: age of the patients, character of the tumour (based on the pathological result), size of the lesion, type of the surgical procedure, duration of the hospitalisation and postoperative complications. RESULTS: 109 girls had ovarian tumours operated--54 times laparoscopy and 55 laparotomy times were performed. An average age of patients who underwent laparoscopy was 16.2 years, in case of laparotomy: 15.3 years (p > 0.05). An average size of tumours excised in laparotomy was 82 mm (60-190 mm), whereas in laparoscopy 64 mm (30-80 mm) (p > 0.05). The most common laparotomic procedure was the ovarian cystectomy (63%) and cystovariectomy (32%), while during laparoscopy the cystectomy was performed in 92% (p > 0.05). Duration of the laparoscopy was shorter, average was 46.7 min, whereas mean time of laparotomy was 49.2 min (p > 0.05). Also duration of postoperative hospitalisation was longer in case of laparotomy, its average time was 5.4 days in comparison with laparoscopy--2.8 days (p < 0.05). CONCLUSIONS: Laparoscopy performed in adolescents due to benign ovarian tumours seems to be a very safe way of the surgical treatment. Moreover, laparoscopy reduces duration of hospitalisation and convalescence, also giving a nice cosmetic effect.     

The insertion/deletion polymorphism (I/D) of the ACE gene in pregnant women with excessive weight gain

INTRODUCTION: The body mass gain is conditioned by lifestyle, as well as many environmental and genetic factors. Recent studies suggest that renin-angiotensin system (RAS) plays a fundamental role in process of growth and differentiation of adipocytes through the acting of angiotensin II and seems to be a significant factor in excessive weight gain development. The purpose of this study was to determine the frequency and significance of insertion/deletion polymorphism (I/D) of the ACE gene in pregnant women with excessive weight gain. MATERIALS AND METHODS: The examined group consisted of 212 pregnant women, including 107 women with normal (DeltaBMI< or =5) and 105 women with excessive weight gain (DeltaBMI>5). Genomic DNA was extracted from venous blood. The I/D polymorphism of ACE gene was determined by polymerase chain reaction (PCR). RESULTS: During the course of the study we did not observe the statistically significant higher frequency of ACE genotypes in any of the two investigated groups of women with normal and excessive weight gain. Nevertheless, an overrepresentation of II genotype frequency in group with excessive weight gain has been observed (33.3 vs 21.5%, p=ns). The same findings were visible as far as the frequency of I allele in group with excessive weight gain was concerned (55.2 vs 45.8%, p=ns). The frequency of observed genotypes was in agreement with Hardy-Weinberg equilibrium. CONCLUSIONS: Although overrepresentation of II genotype and I allele in the group of pregnant women with excessive weight gain (DeltaBMI>5) has been observed, a close correlation between II genotype and higher risk of overweight could be not indicated (due to the lack of significant difference). The results should be confirmed in a more numerous group of pregnant women. At this stage the results of the study did not suggested the presence of association of I/D polymorphism of ACE gene with weight gain in investigated group of pregnant women.     

MET receptor is a potential therapeutic target in high grade cervical cancer

Cervical cancer is one of the leading causes of death among women suffering from tumors. Current treatment options are insufficient. Here, we investigated the MET receptor as a potential molecular target in advanced cervical cancer. Downregulation of MET receptor expression via RNA interference in different cervical carcinoma cell lines dramatically decreased tumor growth and forced tumor differentiation in vivo. MET receptor silencing also led to a dramatic decrease in cell size and a decrease in proliferation rate under normal and stress conditions. MET receptor downregulation also resulted in decreased cyclin D1 and c-myc levels but did not increase apoptosis. Subsequent experiments showed that downregulation of the MET receptor decreased the expression of a key regulator of the epithelial-to-mesenchymal transition, SLUG. and increased the expression of E-cadherin, a hallmark of the epithelial phenotype. Moreover, MET downregulation impairs expression and signaling of CXCR4 receptor, responsible for invasive phenotype.Taken together, our results strongly suggest that the MET receptor influences the oncogenic properties of cervical carcinoma cells in vitro and in vivo. These findings highlight a unique role of the MET receptor in cervical carcinoma cells and indicate the MET receptor as a potential therapeutic target for advanced cervical carcinoma.     

Use of covered Cheatham-Platinum stents in aortic coarctation and recoarctation

We inserted covered Cheatham-Platinum stents in 4 patients, ranging in age from 12 to 19 years, who weighed between 45 and 94 kg. All the patients had aortic coarctation, with surgical repair having been attempted previously in one, and with balloon dilation having been performed as the primary treatment in two, resulting in formation of aneurysms. The fourth patient had not received any treatment. The gradients were reduced from 10 to 40 mmHg before insertion of the stent to 0 to 5 mmHg after stenting. No complications were encountered. All the patients are well at an interval of 3 to 14 months after stenting.     

Acute coronary syndrome after amphetamine use in a young male with myocardial bridging--a case report

Acute coronary syndrome after amphetamine use in a young male with myocardial bridging - a case report. A case of a 19-year-old male hospitalised due to acute coronary syndrome following amphetamine use is presented. Coronary angiography revealed the presence of myocardial bridging causing a 90% stenosis of the left anterior descending coronary artery. The patient was treated conservatively and the outcome was uneventful.